no, No, NO granite! Granite tends to be rather radioactive (particularly avoid
the pink stuff). Any audiofool worth his tin ears can't have no stinkin'
alpha/beta/gamma particles mucking with his music!
BTW, before I bought my house, I tested all the granite surfaces with my
rather nice
Check out the semi-Arduino + OLED LCD that Sparkfun will be selling soon...
it's tiny, fairly cheap, and can run on 3.3 to 18 volts. Looks like it will
be very useful for a lot of small projects. Unfortunately, the OLED does not
appear to have a touch screen.
I'm not sure how the Arduino environment handles interrupts, but in C you need
to declare any variables altered by an interrupt as volatile so that the
compiler optimization routines know not to assume they contain known values.
Also any code that accesses them needs to do so with interrupts
Well, where interrupts are involved, NEVER assume something about how the
code SHOULD/MIGHT be working. It is easy enough to disable interrupts before
accessing the volatile variables and restore them afterwards. This is by far
the simplest and most reliable way to do it correctly (no messy
Some of the STM DIscovery boards are less than $10... search mouser.com for
STM Discovery
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to
What are these wrist watches of which you speak? I saw some old geezer
wearing some sort of clock bracelet a few years ago. Are they similar? ;-)
___
time-nuts mailing list -- time-nuts@febo.com
To
When I was playing with an Adafruit GPS, it appeared that if it thought you
were not moving it would go into a pseudo-position-hold mode and the output
coords would not change. It took it a while to start outputting new coords
when you started moving again. This test was at walking speeds.
The Neo-6M based module (Crius CN-06) is available from HobbyKing for $20
(sometimes on sale for $16). You do have to add the wire to access the 1PPS
signal.
In my testing, I prefer it over the Adafruit Ultimate GPS. The Neo-6M seemed
to a a little more sensitive (could get reliable lock
I have done a PCB that has connectors/mounting holes for the Adafruit, Crius
CN06 (uBlox Neo 6M), and Resolution-T and -SMD receivers. It has a DB9, 3.3V
regulator, and MAX232A chip. It can drive the 1PPS signal (either polarity) to
the CD signal on the DB9. Power to the circuitry can be
There is code in Lady Heather that does all this (independent of operating
system settings). Plus code for calculating and displaying dates in numerous
calendars. Also calculating various holidays, sun and moon position/phases, .
etc.
Hint if you want to write calendarish code... it helps
Ahh, but with Lady Heather you can specify the time zone offset (down to the
second) and the when the daylight savings time switchovers occur. And from
experience, I can tell you that the code to do it is a royal pain in the
ass... not all that hard to do, but a pain to test.
I am building a weather sensor that includes a ultrasonic anemometer to measure
wind speed, direction, and air temperature. It uses 4 cheap ($1 each) HC-SR04
ultrasonic rangefinder modules that output a pulse width proportional to the
time of flight of the sound signal (topic is time nut
The project sounds like a fun hack -- I would be curious as to the resolution
you achieve with these modules.---
The best description on the net about building a sonic anemometer is one by
Hardy Lau:http://www.technik.dhbw-ravensburg.de/~lau/ultrasonic-anemometer.html
I have also built one
I ran across this very issue when trying to calibrate my barometer chip against
the NWS station located less than two miles away. Their numbers for millibars
and inches of mercury do not agree. I sent them an email and asked what was
going on. They said their instruments read out in
I should mention that the circuit that I attached in the previous post does not
output at 49.152 MHz The output is the third (or fifth?) harmonic of the
crystal frequency...
___
time-nuts mailing list --
I build and fly large model rockets. Many use carbon fiber in their
construction. I can tell you that carbon fiber does conduct electricity...
not quite as well as pure metals, but pretty darn good... and the conduction
is anisotropic (better conduction along the fibers than across their
I have had great difficulty getting various MAX3232's to work reliably on 3 ..
3.6V.The datasheet shows the capacitor values you need to use for various
voltage ranges... but no joy. The DC-DC converter does not produce the proper
output voltages. Check the V- and V+ nodes for around +/-
Maybe... maybe not. Some of the Rb's store the tuning word in the processor
EEPROM and those have a rather limited number of write cycles.
You can change the DDS tuning words almost as many times per minute or per
second as you wish to achieve the desired average accuracy.
Check out the temperature control code in Lady Heather. It uses a nice PID
controller algorithm (from Warren Sarkison) to PWM modulate a fan to stabilize
the environment around the Tbolt. It can achieve millidegree range
stability... I have seen long term RMS values of the temperature plot
There is no standard interface for GPSDOs, but the Trimble TSIP interface as
used by the Thunderbolt/Lady Heather would be an excellent place to start and
include. Make the unit smart enough to run unattended, but add enough
monitoring commands so Lady Heather, etc can be used to monitor
Yes I have... I have built several sensor type boards that use an ATMEL chip
as the processor. They output data in a TSIP packet format that tricked up
versions of Lady Heather can control and monitor. The most complicated one is
probably a LED/Battery analyzer device that measures
Check out these puppies... $16 with logic level interface, $17 with RS-232
interface. Does GPS and Glonass. Has antenna. Has 1pps outut. Can do 10 Hz
updates. I ordered 6 of the RS-232 units and they took about a week to
arrive.
I have not done anything with the 1PPS output yet. I
There are TSIP commands for doing all those things. It should be fairly easy
to adapt them to control your hardware and whatever GPS receiver you are using.
The nice thing about implementing a TSIP interface is being able to use
existing programs like Tboltmon and Lady Heather (over 30,000
You don't want to do freezing point tests with gallium... it really likes to
supercool without freezing. A gallium triple point cell is the way to go.
Good reading here: http://www.nist.gov/calibrations/upload/met15-79.pdf
I once built some precision temperature measurement equipment that we
Yes, the caller ID data has time in it. There are chips out there that
decode caller ID. I signaling format isially is the old Bell 202 modem
protocol. The caller ID devices sort of half way answer the phone line when it
detects the incoming call and the caller ID info is sent after the
An oscillator can take many weeks to settle in after being powered off /
shipped / abused / looked at cross-eyed / etc. It typically takes a
Thunderbolt a month or two to settle down after being shipped from China.
I have purchased about a dozen of these receivers (mostly the RS-232 version
for $1 more). Reyax ships very fast. I get them in about 1 week.
They work well, and are based upon the Ublox MAX-7C. They output independent
GPS and Glonass NMEA messages and don't appear to merge the two systems
They seem to do pretty well. I have mine in devices sitting on my kitchen
floor. It is downstairs in a stucco over wire mesh house. Nearest window/door
is 20 feet away... and it is shaded by a stainless steel covered bridge to the
guest house. Also lots of stainless in the kitchen... they
I just finished laying out a small circuit board for building an extender cable
for the Tek TM500 series mainfames / modules. Prototypes are off being fab'd
at OSHPARK. Should be here in a couple of weeks. It uses two 39/40 pin ribbon
cables (all the power pins use two wires)... e.g.
I think a cable made from ribbon cable edge connectors would be the
easiest/cheapest way to extend the GPIB connector.
Have you thought about making extensions for the smaller connector used to
distribute GPIB in the 5000 series?
I have seen the Jamma kit (I will be using their edge connectors) and John's
design. Their main problem is the hassle of wiring up 56 individual wires.
Also that tends to be not all that reliable... wires tend to break at the
solder joints.
The board that I laid out has two 40 pin ribbon
Yes, all 56 pins are extended, including the PWR pin unique to the 5000
series (it is a power good/power-on reset sort of signal).Several of the
TM500 modules are also double-wides and need two extender cables.
I have not done an extender for the GPIB connector, but that would be easy to
Well, just for grins, I did a small board for extending the TM5000 GPIB
connector. I remember that the last time I extended the GPIB bus by hooking a
ribbon cable to the TM5000 mainframe motherboard it was a bit of a hassle to
get to. These should make life easier...
I did some more playing around with the 3458A memory dumper this weekend. I
built up another system using a different computer/cables/software/GPIB
interface (one I built using an AVR chip that emulates the Prologix RS-232/USB
converter). I noticed than a couple of dumps of the CAL ram
I got in my prototype extender cable boards from OSHPARK.COM today. OSHPARK
only builds boards in multiples of 3 and I only ordered three boards so could
only build one cable. It seems to work very well. I tested it with several
different TM500 and TM5000 modules (using another set of cables
No, that is exactly what they usually do. They want to keep you in the dark
and guessing as much as possible.
I once had a guy claim a product we built infringed his patent. He had a
memorable name. Turns out I remember talking to him after he had bought one
of our products a couple of
Well, after doing my TM500 extender cables, I was thinking of doing an
extender board for the HP5370 boards. It would take two 36 pin extender cards
to extend a card out of the card cage (the count chain board has a different
connector spacing than the other boards so splitting the extender
Boards would come with the edge connector.
I just finished laying out 36 pin and 44 pin 0.156 extenders. They are 125mm
tall (HP5370 boards are 100 mm tall). I could go to 150 mm tall if that would
help them to be useful with other equipment.
You could hack up the boards for use with
It usually takes 2-3 weeks to get boards back once sent to the fab (in China).
Supposedly the boards that I am having them do for another project should be
here today and I can verify their quality.
I also laid out a 20 pin extender to connect the input board to the front
panel, but I don't
Yes, can ship world wide. Not sure what the postage will be, but should not
be too bad.
I'm leaning towards a 3 card set as the standard. Two of the 36 pin extenders
and one of the 44 pin. There are a couple of other misc boards in the machine
with different pin counts (oscillator,
Frankly, anybody that builds up a Simple Switcher type converter from scratch
is more than a little nuts and/or awfully lonely. You can buy small,
adjustable pre-built boards (buck or boost configs) off of Ebay for as little
as a dollar each... including shipping from Old Cathay. I usually
There are actually quite a few makers of what you seek...
EMCO H40P will do 3.75 mA at up to 4000V... voltage selected by a 0..5V input.
Also check out PPM's offerings...
http://www.ppmpower.co.uk/high_voltage_dc_dc_converters/
And UltraVolt's 4AA series:
No web page, but a little description here. It has changed quite a bit from
the original description. Now uses TAOS color sensors. Suppors Melexis IR
thermometer chips. Has 16 bit A/Ds. Processor is an ATMEGA 1284. The control
program is based on Lady Heather. Besides LEDs it can
Whoops... that last message should have gone to volt-nuts...
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions
Version 4 of Lady Heather(not yet released) has rollover compensation built in.
If the detected date is less than the current system date it adds 1024 weeks
to the Tbolt date/time by default. You can also specify an alternate rollover
offset or disable rollover compensation.
The sun can have some effects on GPS signals, particularly when doing
ultra-precisiony sorts of things.
Version 4 of Lady Heather calculates the sun (and moon) positions (and moon
phase) and can display them as part of the satellite position map (and analog
watch display). This feature was
The TM500/5000 and HP5370 extender kits are now available (actually they were
ready a few weeks ago, but I was going to be out of town and did not want to
leave people hanging).Prices are:HP5370 extender card kit - has 2 x 36 pin
extenders and 1 x 44 pin extender. $30 setTektronix TM500/TM5000
If you want to add wi-fi to a project, take a look at the ESP8266 wifi
system-on-a chip. It has a wifi transceiver and a 32 bit processor on a single
chip. People have been getting 300 meter range with a PCB antenna. There is
now a GCC compiler for it... lots of work going on here:
I suspect that 90% of the work could be done with a single kit. That will get
one card out of the chassis. But, there are always those annoying problems
where getting two cards out can make life a little easier. With two kits you
could also hack up the extra 44-pin board to make a smaller
People are always complaining that US test equipment is unobtanium overseas.
So far I have shipped out around 30 of the HP5370 extender card kits. It is
rather interesting that well over half have gone international: Canada, UK,
Netherlands, Denmark, Sweden, Spain, France, Portugal,
if New Mexico is really a legitimate US state.
I dunno, I've been there. Was exposed to bubonic plague. And a friend caught
some wonderful blue corn tortilla parasite. And the interstate highway was
two narrow strips of asphalt (one for each pair of wheels) separated by a few
feet of grass.
Happened to a friend of mine. All his Arduino stuff died. This could be the
reason:
http://www.eevblog.com/forum/reviews/ftdi-driver-kills-fake-ftdi-ft232
Short story: FTDI released a new version of their USB driver (via Windows
automatic updates no less) that bricks other vendor's
I would avoid those RC lipo packs like the plague or Ebola... they are made up
of pouch cells (not AA sized cells) and many/most are of dubious quality. They
are designed to last a few cycles of very high-output runs. They tend to puff
up and go unstable and do fun things like spontaneously
A friend of mine is looking for an ADC that can do 5 bits at 20-40
gigasamples/second... there is a timing related component to the project. Any
ideas of who makes a decent beastie? It needs to supply continuous data so
things like a fancy scope won't do...
Oh, it gets much more fun than that... try doing it with 32 channels.
I haven't a clue what this system will use... and frankly am rather glad I
don't have to do it.
I have built some rather large systems that were a bit ahead of their time.
Early 80's did a 256,000 custom processor
You could try submitting your data to zunzun.com It will fit it to around
40,000 different curves and find the best ones.
Beware that with all curve fitting formulas, once your live data starts to
wander out of the range of your original curve fit data, things can go rather
badly...
If you are going to back up the clock with AA cells, use lithium primary AA
cells. They will last longer, plus they don't leak. EVERY alkaline cell will
eventually leak... they don't call 'em Alkaleaks for nuthin'
It's surprisingly large. I have a scale that can measure 20g down to a
microgram (and worked on one that can do a gram at nanogram resolution).
Taking the microgram scale up one floor in a building was easily detectable...
I don't remember the exact number but it think it was in the 1
Found it on page 17 of Mettler's excellent article:
Adverse Influences and Their Prevention in Weighing
http://us.mt.com/dam/mt_ext_files/Editorial/Generic/2/Weigh_Uncertain_Number1_0x0003d6750003db6700091746_files/adverse_influences.pdf
It works out to be -0.3 ppm/meter.
BTW, be careful with micronized teflon... it is a very powerful oxidizer
and forms highly combustible/explosive/nasty mixtures with things like powdered
or finely divided metals. Particularly magnesium, aluminum, and titanium.
More than one machinist has been surprised by exploding swarf.
I wonder how well Viton would work? Viton is soluble in acetone and should
make coating much easier.
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to
I have seen this caused by the oscillator not responding to the EFC signal.
Fixed it by swapping in a MV-89 oscillator.
The oscillators used in these units don't output an oven temperature monitor
signal.
___
Ouch! some circuits just sound too painful to think about... ;-)
---
The Twisted Johnson Ring Counter...
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to
I once bought an HP16700 series logic analyzer off of Ebay that had a directory
filled with porn on it... but that is a Unix machine.
for good reason. A friend's scope picked up a virus.
___
Lady Heather supports a digital clock display. You can zoom it to full screen.
It would not be difficult to add the two time zones to that display.
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe,
I did this on a lark one day. 5065A - doubler block - tbolt Seemed to work
very well, but I didn't do any serious testing of it.
---
There's a third alternative as well. You might consider using your 5065A as the
LO in a GPSDO. This will sacrifice some short- and mid-term
I think only TIMER2 on the AVR has the clk/4 limitation. The other timers can
count at full speed.I know that I have counted at 8-12 MHz before...
___
time-nuts mailing list -- time-nuts@febo.com
To
Although the Trimble oscillator has superb phase noise performance, it has
TERRIBLE temperature sensitivity. It appears to be a single oven oscillator,
not a double oven. The PWM'ed fan temperature control implemented in Lady
Heather effectively makes the unit a double oven. Also, by
BTW, Lady Heather has support for several versions of the Mayan and Aztec
calendars. Also Druid, Herbrew, Islamic, Indian, and many others.
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe,
Yes, you can have a GPSDMC (GPS disciplined Mayan calendar). You can also
specify your preferred calendar correlation constant (a +/- offset to the start
of the calendar) to satisfy the whims of when your favorite deity demands
sacrifices.
Also, Lady Heather does sidereal time (LMST or
The closest thing to a manual is the comments at the start of the file
heather.cpp in your Lady Heather installation directory...
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to
Please read through the release note comments at the start of the heather.cpp
file in your Lady Heather installation directory for some info on the temco and
drift calculation features.
The drift numbers assume either a constant temperature or a decent DOXCO that
is not affected by
Take a close look at the photos of Malones nice little voltage reference boards
(http://www.voltagestandard.com/Home_Page_JO2U.html). The voltage reference
chip is mounted on an isolated peninsula of PC board material to help isolate
it from stress due to environmental changes.
A123 20Ah LiFePO4 cells have an internal resistance in the milliohm range.
Their M1 26650 format cells are around 8 milliohms. Most high capacity (3000
mAh) 18650 style lithium cells are around 10-15 milliohms.
I looked into the 1PPS/2PPS issue on these Nortel units when I added support
for them into Lady Heather. They do not appear to respond to the commands for
changing to 1PPS. Also, they do not appear to save the oscillator
disciplining parameters into EEPROM (at least using any of the
Another nifty product from 3M is their cold shrink tubing. It is a rubber tube
stretched over a peel-able spiral core. You insert the tube over the
cable/connector and peel out the core. The rubber shrinks down over the cable
and forms a tight seal. It is typically used on buried cables. I
Nope, been there, tried that. Supposedly Trimble had a firmware option for
doing/reporting proper carrier phase stuff, but I have never seen a Tbolt with
it.
---
I don't know if the Trimble TBolt or Res-t give out enough information to
generate RINEX
I have been working a version 4.0 of Lady Heather. One thing that I would like
to implement is better error checking on the serial data port...
parity/framing/overrun errors. I haven't been able to find much valid info on
how to coax this info out of Windows... Does anybody know how?
The 48-hour precision survey in Lady Heather uses a statistical weighted median
filter to arrive at its final location instead of a simple average of fixes.
It processes data of one minute, hour, and overlapping 24 hour intervals to
calculate the final position. It can produce a location
Earth circumference is around 25,000 miles - 132E6 feet. 24 bit mantissa (23
bits plus sign) gives a resolution in this application of around 15.7 feet
since negative measurements don't apply.
---
Oh... 24 bit mantissa should give 1.25 m resolution if my headcounting is
The data was collected in 0.1 dB / AMU steps. There was a lot of noise in the
raw data (maybe +/- 1 dB or AMU), but the general trend of the curve was quite
distinct. I smoothed it out by hand and filled in a few (maybe 15) of the
missing steps that had no signal.
The 0.1 resolution of
Lady Heather will let you know when it is April Fool's day (and a bunch of
other days) if you are running one of the latest beta versions...
-
One person on the list asked if it was the first of April already (April Fool's
Day).
You should check out the info I did when I did some reverse engineering on the
5650A...
http://www.ko4bb.com/dokuwiki/doku.php?id=precision_timing:rubidium_oscillators
_
Hotmail: Trusted
If it's the one that I think it is... look closely at the photo. The shafts
on two of the pots are sheared off at the panel. These are the display update
control and the external arming level control. These were custom HP pots with
a funky (and delicate) switch. They had brittle
Apparently the earthquake in Chile has shifted he earth's axis enough to
shorten the day by 1.26 microseconds. Darn, I now have to readjust my
Accutron watch.
_
Hotmail: Powerful Free
Pretty trivial to do with GPS where a 1 ns error is under 1 foot of position
error (and a geodetic grade GPS can give sub-millimeter accuracy)... even a
cheap consumer grade unit is under 10 feet of error. 1.26 us of orbital
change is over 1100 feet of error.
One trick is to compare the
Hello Bruce,
I tried to send you an email directly, but your spam filtering seems to be
getting in the way again.
Ebay item 150418469678 has a Magellan 5000 GPS board on it... might be handy
to have a spare for your unit. It is from an Odetics unit.
Mark
Google USB Hourglass or visit http://home.comcast.net/~hourglass/ and you
will see that it has already been done. His application was as a random
number generator. Should be available as a kit soon...
I've had the pleasure of fixing way too many 5370A and 5370B front panels.
It's been a while so these musings may be clouded... also beware of the two
or three different front panel designs. Also there are hybrid 5370A's out
there with 5370B front ends.
There are 4 pots on the front
99.95 ns is a typical number for the period reading at minimum gate time. Set
the gate time to 1 sec. My 5370A shows 99.999 999 9650 +/- 50 at 1 sec gate
time.
From my experience it can take at least a couple of months of continuous
operation for the oscillator in an unused 5370 to
Yes, I replace the standard HP fan with a MUCH quieter one. I get mine from
a local surplus shop. It is made by AAVID. it draws 120 mA at 12V and I run
it off the 10V supply (which is somewhat over 10V).
I don't have one handy to get the part number. They also have a 160 mA model
Are you sure that it has a variable speed fan? My 5372A has a pretty quiet
fan and I have never tried to change it. I am assuming that it uses the same
117V fan as the 5371A. That thermal switch may be a power supply shutdown.
I have a couple of 5371A's that are a different matter.
Gawd, tell me about it... I just got through rebuilding the drive roller in
half a dozen Tektronix YT-1 and YT-1S chart recorders for the
1502B/1520C/1503B/1503C TDR's. The recorders were built by AstroMed and the
roller was made of a black urethane that reverts back to its primordial
It doesn't get any better than Ebay item 270262189976... I've tested a couple
dozen antennas and nothing comes close to what it does... It's big. It's
pricey (but FAR less than the $2000+ original cost). It's good.
---
I'm looking for a decent outdoor antenna for my Thunderbolt...
That's the 1502/1503 chart recorder that uses a hot stylus and paper roll with
a punched timing track. Paper is available at $25-$36 a roll (min purchase 10
rolls). I have a mod that lets you use $1-$2 a roll ECG paper.
The 1502B/1503B/1502C/1503C are a different animal. Their chart
All the choke ring antennas were similar in performance. The Aero/Leica one
is optimized for the L1 freq only.
All the other choke rings that I tested did L1/L2 which compromises performance
a bit which did show up in the data (but at a level that could just have been
random luck of the
The current Lady Heather beta release has several antenna survey commands.
You can plot signal level vs azimuth (actually, not all that useful since high
elevation sats cross a lot of elevation angles and obsucre low elevation angle
data that tends to have a much greater effect on
Aghhh, magic pie! Betterer than forbidden donuts...
--
Maybe its just luck and I have found a Magic pie pan
_
Hotmail: Trusted email with powerful SPAM protection.
Not to mention that yesterday was Pluto's birthday!
_
Hotmail is redefining busy with tools for the New Busy. Get more from your
inbox.
At one time I thought the Thunderbolt had some carrier phase capabilities...
it does not. I found a couple of undocumented (for the Thunderbolt) status
messages that indicate that the Thunderbolt firmware does not have the carrier
phase routines installed.
It does output the code phase
1 - 100 of 1485 matches
Mail list logo
